The present invention relates to a method of vertically conveying packets of cigarettes.
Here and hereinafter, "vertically" is intended to mean any movement comprising an upward or downward component.
The present invention may be used to advantage for transferring packets of cigarettes from the output of a cellophaning machine to the input of a cartoning machine, to which the following description refers purely by way of example.
In cigarette packing systems comprising a cellophaning machine and a cartoning machine connected in series, the packets of cigarettes are fed from the output of the cellophaning machine to the input of the cartoning machine along a path comprising a normally upward change in level.
In known systems, the change from one level to the other is normally made by means of a stacking device, which normally comprises a reciprocating pusher for successively receiving the packets at the output end of a normally horizontal path, and for pushing them successively into a vertical conduit inside which a stack is formed. On emerging from the top end of the conduit, the top packet in the stack is removed by a second pusher, which feeds the packets successively on to a normally horizontal conveyor.
The above method involves several drawbacks, foremost of which are the necessity of feeding the packets in steps to the input of the conduit, and the rigidity of the system, which does not allow the output direction of the packets from the vertical conduit to be adapted to any arrangement of the cartoning machine with respect to the cellophaning machine.
The first of the above drawbacks has been eliminated using counter-rotating screw lifting devices by which the packets are fed successively between two screws separated by such a distance as to engage the opposite ends of the packets, which are lifted by the two screws along a vertical guide interposed between the screws.
Though the above method does allow, if necessary, for continuously feeding the packets to and through the lifting device, the structure of the device is such that the change in level is made by feeding the packets parallel to themselves at all times. As a result, throughout their upward movement, the packets maintain the same orientation, which cannot be adapted as a function of the position of the cartoning machine with respect to the output of the cellophaning machine.